1. Technical Field
The present invention relates to an image display device.
2. Related Art
In the past, a projector provided with a light source, a light modulation device for modulating the light emitted from the light source, and a projection optical device for projecting the light thus modulated on a projection surface such as a screen in an enlarged manner has been known as an image display device. As such a projector, there is known a projector, which performs temperature control of a solid-state light source adopted as the light source (see, e.g., JP-A-2007-156438 (Document 1)).
The projector described in Document 1 is provided with each of the solid-state light sources respectively emitting colored lights of red, green, and blue, and in addition, there are disposed temperature detection devices (temperature sensors) provided respectively to these solid-state light sources, and for detecting the temperature of the solid-state light sources, and temperature regulation devices (fans) for regulating the temperature of the solid-state light sources.
Here, the solid-state light sources each have an output wavelength varying in accordance with the temperature change. For example, in the case in which the temperature of the solid-state light source rises, the peak wavelength of the light to be output is shifted to the longer wavelength side, and in the case in which the temperature falls, the peak wavelength is shifted to the shorter wavelength side. To cope with such a variation of the output wavelength as described above, the projector suppresses the variation of the output wavelength by suppressing the temperature change by controlling the temperature regulation device so that the temperature of the light source is kept at the set temperature in accordance with the temperature of the light source detected by the temperature detection device.
Incidentally, even in the case of the solid-state light source manufactured so as to have a predetermined wavelength peak, a shift in the peak wavelength due to the individual difference may occur in some cases even if the solid-state light sources are lit in the same conditions.
Therefore, in the case of adopting a plurality of solid-state light sources for the light source device for the purpose of increasing the luminance of the light to be emitted, it is difficult for the configuration of the temperature regulation device described in Document 1 mentioned above to perform the temperature control in accordance with each of the solid-state light sources, and there is a problem that it is difficult to correct the shift of the peak wavelength between the solid-state light sources.